Polymeric piezoelectric composite compositions including passive polymer matrices

Abstract

Disclosed is a composite comprising: a polymer matrix formed from one or more of a monomer or a precursor polymer; and an in-situ dispersion of a piezoelectric ceramic filler and an ionic additive within the polymer matrix, wherein the composite exhibits a d33 of at least 1 pC/N when measured using a piezoelectric meter. Disclosed also herein are methods of forming the composite.

What is claimed: 
     
       1. A composite comprising:
 a thermoplastic polymer matrix synthesized in-situ from a monomer mixture or a precursor polymer in the presence of a dispersion of a piezoelectric ceramic filler and an ionic additive and in absence of an organic solvent, the monomer mixture or the precursor polymer comprising from about 70 weight percent (wt. %) to about 95 wt. % of an alkyl methacrylate and from about 5 wt. % to about 30 wt. % of a hydroxyalkyl methacrylate based on the total weight of the monomer mixture or the precursor polymer. 
 
     
     
       2. The composite of  claim 1 , wherein the composite exhibits a d 33  of at least 1 pC/N when measured using a piezo meter. 
     
     
       3. The composite of  claim 1 , wherein the piezoelectric ceramic filler is present in an amount of from about 5 wt. % to about 90 wt. % based on the total weight of the monomer mixture or the precursor polymer. 
     
     
       4. The composite of  claim 1 , wherein the ionic additive is present in an amount from about 0.01 wt. % to about 4 wt. % based on the total weight of the monomer mixture or the precursor polymer. 
     
     
       5. The composite of  claim 1 , wherein the piezoelectric ceramic filler comprises barium titanate having a particle size ranging from about 300 nm to less than about 700 nm. 
     
     
       6. The composite of  claim 1 , wherein the piezoelectric ceramic filler has a particle size less than 4000 nm. 
     
     
       7. The composite of  claim 1 , wherein the ionic additive comprises an organic cation and a balancing anion. 
     
     
       8. The composite of  claim 1 , wherein the ionic additive is a liquid. 
     
     
       9. The composite of  claim 1 , wherein the ionic additive is 1-butyl-3-methylimidazolium hexafluorophosphate. 
     
     
       10. The composite of  claim 1 , wherein the composite is an 0-3 composite. 
     
     
       11. The composite of  claim 1 , wherein the composite has a surface roughness of less than 10 μm when measured using a profilometer. 
     
     
       12. The composite of  claim 1 , wherein the piezoelectric ceramic filler has a d 33  of at least 100 pC/N. 
     
     
       13. A composite comprising:
 a thermoplastic polymer resin matrix synthesized in-situ from a monomer mixture or a precursor polymer in the presence of from about 5 weight percent (wt. %) to about 90 wt. % of a piezoelectric ceramic filler and from about 0.01 wt. % to about 4 wt. % of an ionic additive, the monomer mixture or the precursor polymer comprising from about 80 wt. % to about 95 wt. % of an alkyl methacrylate and from about 5 wt. % to about 20 wt. % of a hydroxyalkyl methacrylate, 
 wherein the composite is formed as a solvent-free dispersion and exhibits a d 33  of at least 1 pC/N when tested using a piezometer, and wherein a surface of the composite exhibits a surface roughness of less than 10 μm, wherein the weight percent of each of the alkyl methacrylate, the hydroxyalkyl methacrylate, the piezoelectric ceramic filler, and the ionic additive are based on the total weight of the monomer mixture or the precursor polymer. 
 
     
     
       14. A composite comprising:
 a thermoplastic acrylate copolymer matrix having a comonomer capable of forming hydrogen bonds, wherein the thermoplastic acrylate copolymer matrix is synthesized in-situ from about 70 weight percent (wt. %) to about 95 wt. % of an alkyl methacrylate and from about 5 wt. % to about 30 wt. % of 2-hydroxyethyl methacrylate in the presence of a dispersion of a piezoelectric ceramic filler and an ionic additive. 
 
     
     
       15. The composite of  claim 14 , wherein the piezoelectric ceramic filler comprises barium titanate having a particle size ranging from about 300 nm to less than about 700 nm.